Choice "b" is correct. Under Section 1245, the amount of depreciation in excess of straight-line depreciation is irrelevant (the "excess depreciation" rule is a Section 1250 rule and applies to real property). In this question, $30,000 of depreciation was deducted and, at first glance, the answer would appear to be $30,000. However, Section 1245 actually only requires that the lesser of the depreciation taken ($30,000) or the gain recognized ($200,000 - $180,000 = $20,000) be recaptured.

Choice "a" is incorrect. The $13,000 is the difference between the $30,000 depreciation that had been deducted and the $17,000 "excess" depreciation. That amount is not used anywhere.

Choice "c" is incorrect. The $17,000 is the amount of "excess" depreciation. As indicated, this amount is related to Section 1250 depreciation recapture, not Section 1245. Section 1245 requires depreciation recapture regardless of the method of depreciation.

Choice "d" is incorrect. The $30,000 is the depreciation that had been deducted. Normally, that would be the amount subject to Section 1245 recapture. However, only the gain recognized is recaptured in this question.